Schausberger Peter, Sato Yukie
Sugadaira Research Station, Mountain Science Centre, University of Tsukuba, Ueda, Nagano 305-8577, Japan.
Department of Behavioral and Cognitive Biology, University of Vienna, Althanstrasse 14, 1090 Vienna, Austria.
Biology (Basel). 2020 Oct 26;9(11):360. doi: 10.3390/biology9110360.
Optimal outbreeding and kin selection theories state that the degree of kinship is a fundamental determinant in any mating system. However, the role of kinship in male choice and alternative reproductive tactics (ARTs) is poorly known. We assessed the influence of kinship on male choice and expression of ARTs in two populations of two-spotted spider mites . Male spider mites guard premature females, which is an indicator of mate choice, and may conditionally adopt fighting or sneaking tactics to secure access to females. Males competing with kin or non-kin were offered one kin or non-kin female (experiment 1) and single males were presented a choice of kin and non-kin females (experiment 2). Under kin competition, males of both populations were more prone to guard non-kin than kin females at a 3:1 fighter:sneaker ratio. Under non-kin competition, all males were fighters. Under no-choice, males used novelty as indicator of genetic dissimilarity, serving as absolute decision rule for outbreeding. Under choice, comparative evaluation allowed males to preferentially guard females with higher reproductive potential. Overall, our study suggests that male spider mites can assess kinship of rivals and prospective mates. Kin discrimination allows adaptive, context-specific non-random mating preference and adjustment of ARTs.
最优远交和亲缘选择理论表明，亲缘关系程度是任何交配系统的一个基本决定因素。然而，亲缘关系在雄性选择和替代生殖策略（ARTs）中的作用却鲜为人知。我们评估了亲缘关系对二斑叶螨两个种群中雄性选择和ARTs表达的影响。雄性叶螨会守护未成熟的雌性，这是配偶选择的一个指标，并且可能会有条件地采取争斗或偷腥策略以确保接近雌性。与亲缘或非亲缘个体竞争的雄性被提供一只亲缘或非亲缘雌性（实验1），而单独的雄性则被给予亲缘和非亲缘雌性的选择（实验2）。在亲缘竞争中，两个种群的雄性在3:1的争斗者:偷腥者比例下，比起守护亲缘雌性，更倾向于守护非亲缘雌性。在非亲缘竞争中，所有雄性都是争斗者。在无选择情况下，雄性将新奇性作为遗传差异的指标，作为远交的绝对决策规则。在有选择情况下，比较评估使雄性能够优先守护具有更高生殖潜力的雌性。总体而言，我们的研究表明雄性叶螨能够评估对手和潜在配偶的亲缘关系。亲缘识别允许适应性的、特定情境下的非随机交配偏好以及对ARTs的调整。
